The same cells that take in information about what we see and hear – and where we are – also contain circadian clocks that mark down the time of that learning.
Lévi came to the study of timed pharmaceutical intervention through a study of traditional Chinese medicine, the core tenets of which are rooted in chronology – physiological differences between day and night, as well as the seasonal flare-ups of various types of ailments.
According to Weijun Zhang of the David Geffen School of Medicine at the University of California, Los Angeles, the body is divided into 12 meridians, which map loosely onto the bi-hourly time markers of ancient China, and an acupuncturist might take the timing of symptoms into account when choosing body points to target.
The overall idea of timing opportunities in medicine is newly relevant. Imagine a future in which every prescription carries a label with timing instructions. Knock out the cardiomyocyte clock genes that keep track of the time of day, and heart attacks at any time of day have the same minimal damage.
Imagine a future in which every prescription carries a time stamp, and even an over-the-counter remedy such as Paracetamol, profoundly rhythmic in its liver toxicity, sports a label with timing instructions.